It is known that corticoid steroids are effective on different animal tumors. It is also known that chlorambucil, melphalan and sarcolysin have the same effect. By esterification of corticoid steroids with acids of said types it has now been shown that the products so obtained have an effect which is far superior to that prior known.
It is an object of the present invention to provide compounds of nitrogen mustard type which are sufficiently non-toxic to be administered, for example, orally or by intramuscular or intraperitoneal injections.